1. Field of the Invention
The present invention relates to a printing machine including an ink supply that has a degasser.
2. Description of Related Art
There are known printing machines provided with an inkjet head for propelling out ink droplets, and an ink supply as a measure for supplying ink to the inkjet head. In such printing machines, the inkjet head has a set of piezoelectric elements or like elements exerting pressures on flux of ink, when printing images. This propels out droplets of ink onto a print sheet or such, to make the printing.
In such printing machines, ink contains dissolved gases that, if contained much, have tendencies to form bubbles depending on ink temperature and pressure variations while printing. Formed bubbles may absorb substantial pressures exerted on associated flux of ink, resulting in a failure to discharge ink, as an issue. To this point, there are known printing machines including a degasser for reducing contents of gases dissolved in ink.
There has been an inkjet printing machine disclosed in Japanese Patent Application Laying-Open Publication No. 2007-190703, including an ink circulation system for circulating ink, a dissolved gas amount acquirer for acquiring information on an amount of dissolved gases in ink, a three-way valve installed on an ink line in the ink circulation system for route selection among branched ink routes, a degasser installed on one of the ink routes branched at the three-way valve, and a pressure loss compensator for compensating a pressure of ink caused by the degasser.
This printing machine has been adapted to work after initiation of a printing, to operate upon a determination made on an excessive amount of gases dissolved in ink, to control the three-way valve, to conduct flux of ink through the ink route having the degasser installed thereon. This has afforded to supply flux of degassed ink to an inkjet head, there being a pressure loss caused in flux ink flowing through the degasser. The pressure loss compensator has been operated to make a pressure adjustment of such flux of ink.